Capsule for two-component materials

ABSTRACT

Capsule ( 10 ) for two or more components of a material which are to be mixed together, comprising a cartridge ( 11 ) comprising an outlet ( 12 ), a first component chamber ( 13 ) for containing a first component, and a second component chamber ( 14 ) for containing a second component, the two chambers ( 13, 14 ) opening into the outlet ( 12 ); and a piston ( 15 ) which at least with its front end sits in the cartridge ( 11 ), lies with its rear end outside the component chambers ( 13, 14 ) and, when it is pushed forwards, presses the two components out of their component chambers ( 13, 14 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 10/568,247, filed Nov. 14, 2006, now U.S. Pat. No. 7,882,983 whichis a U.S. 371 National Stage Patent Application of PCT/EP2004/007178,filed Jul. 1, 2004, which claims priority from German Patent No. DE 10337 790.5, filed Aug. 14, 2003, and from European Patent No. EP 04 013277.1, filed Jun. 4, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a capsule for two or more components of amaterial which are to be mixed together. The material can be a dentalmaterial, for example an impression material, a temporary restorationmaterial or a filler material.

2. Background

In the dental sector, that is to say the sector involving dentists anddental technicians, various capsules are known for intraoraladministration of materials consisting of one component or of two ormore components which are to be mixed together. There are so-called“compules”, liquid/powder capsules, and paste/paste capsules.

The compule is a capsule having a cannula, a single chamber containing aone-component material and opening at the front into the cannula, and apiston which sits in the chamber at the rear. Such compules can contain,for example, the universal filler material Filtek™ Supreme and theuniversal composite Filtek™ Z250 available from 3M ESPE. For use, theyhave to be inserted into an applicator 62 (shown in FIG. 69) which, forexample, is available from 3M ESPE as Capsule dispenser under articlenumber 5706 SD or from Centrix™. These known applicators 62 each have abody with a handgrip, a holder for receiving the compule in a removablemanner, a plunger, and a drive mechanism for the plunger. When thecapsule sits in the holder and the drive mechanism is actuated byclosing the hand, said drive mechanism then pushes the plunger into thechamber from the rear, so that said plunger initially bears on thepiston and pushes it farther forwards. By means of the advance movementof the piston, the material is dispensed from the chamber through thecannula. Such compule applicators 62 are very widely available on themarket.

The liquid/powder capsules contain a liquid component and a powdercomponent which have to be kept separate from one another until the timeof use. Such liquid/powder capsules are, for example, available underthe names Aplicap™ and Maxicap™ from 3M ESPE. These capsules contain,for example, the two components, to be mixed together, of fillermaterials such as, for example, the glass ionomer filler material Ketac™Molar, or the light-cured glass ionomer filler material Photac™ FilQuick, or the silver-reinforced glass ionomer filler material Ketac™Silver Molar, or luting cements such as, for example, the self-adhesiveuniversal composite luting cement RelyX™ Unicem or the adhesivecomposite luting cement Compolute™ or the glass ionomer luting cementKetac™ Cem. These known capsules have a cannula, a large mixing chamberwhich contains the powder and opens at the front into the cannula, apiston which sits at the rear in the mixing chamber, and a foil pouchwhich contains the liquid and covers a hole in the shell or outer wallof the chamber. To use it, the capsule is first activated by applyingpressure in a suitable way to the foil pouch, so that the latter tearsover the hole and the liquid is forced into the mixing chamber. Themixing chamber is larger than the joint volume of the two components, sothat these can be mixed together by vigorous agitation, for exampleusing the capsule mixer devices RotoMix™ or CapMix™ from 3M ESPE. Theythen have to be inserted into a suitable applicator 62, which forexample is obtainable under the name Aplicap™ Applier (shown in FIG. 70)or Maxicap™ Applier from 3M ESPE. These known applicators 62 each have abody with a handgrip, a holder for receiving the capsule in a removablemanner, a plunger 63, and a drive mechanism for the plunger 63. When thecapsule sits in the holder and the drive mechanism is actuated byclosing the hand, said drive mechanism then pushes the plunger 63 intothe mixing chamber from the rear, so that said plunger 63 initiallybears on the piston and pushes it farther forwards. By means of theadvance movement of the piston, the material is dispensed from themixing chamber through the cannula. Such applicators 62 forliquid/powder capsules are likewise widely available on the market.

The paste/paste capsules contain two pasty components which have to bekept separate from one another until the time of use. Such a paste/pastecapsule is known from WO 97/21394, which additionally discloses anapplicator for this capsule. This known capsule has a cannula, a staticmixer, which sits in the cannula, two cylindrical chambers lyingalongside one another and opening at the front into the cannula, and twocylindrical pistons which sit displaceably in the rear of the chambers.The known applicator has a body with a handgrip, a holder for receivingthe capsule in a removable manner, two elongate plungers lying alongsideone another, and a drive mechanism for the two plungers which, when thecapsule sits in the holder, advances these into the two chambers fromthe rear. The chambers contain the two pasty components which, uponactuation of the applicator drive mechanism, are pressed forwards out ofthe chambers and into the cannula by the two pistons which are pushedfarther into the chambers by the two plungers. Upon further flow throughthe cannula, the two component strands are mixed together by means ofthe mixer and finally dispensed as a ready-mixed material from the frontof the cannula.

The paste/paste capsule known from WO 97/21394 cannot be used with theknown compule applicators 62 described above, nor with theabove-described known applicators 62 for liquid/powder capsules, both ofwhich forms are widely available on the market, because these each haveonly a single plunger 63, while the known paste/paste capsule has twopistons.

SUMMARY OF THE INVENTION

The Invention provides the advantage that the capsule according to thepresent invention can be used with an applicator having a single plungerwhich is advanced when the applicator is actuated. Above all, thecapsule according to the present invention can be designed without greatexpense in such a way that it matches the compule applicators alreadyavailable on the market or the applicators for liquid/powder capsules.In this way it is possible to avoid the expense of producing a newapplicator and bringing it onto the market.

A further advantage of the invention results from the fact that thecapsule interface is adapted to be used with existing applicators havinga single plunger. In this way, future developments of paste materialsand appropriate capsules are not limited to two-component systems andare independent from standard mixing ratios as all paste materialspecific details are included in the capsule itself. Thus a modificationof the applicator would not be necessary.

The proposed solutions of the invention all relate to the packaging ofpastes, which are to be understood as including liquid to pastysubstances, preferably for dental applications.

In a first aspect, the invention relates to a capsule for two or morecomponents of a material which are to be mixed together, comprising:

-   -   a cartridge comprising an outlet, a first component chamber for        containing a first component, and a second component chamber for        containing a second component, the two chambers opening into the        outlet; and    -   a piston which at least with its front end sits in the        cartridge, lies with its rear end outside the component chambers        and, when it is pushed forwards, presses the two components out        of their component chambers.

In a second aspect, the invention relates to a capsule for two or morecomponents of a material which are to be mixed together, comprising:

-   -   a cartridge comprising an outlet, a first component chamber for        containing a first component, and a second component chamber for        containing a second component, the two component chambers        opening into the outlet;    -   a first piston which at least with its front end sits in the        first component chamber, and a second piston which at least with        its front end sits in the second component chamber, which two        pistons lie with their rear ends outside the component chambers        and, when they are pushed forwards, press the two components out        of their component chambers.

Since the two pistons lie with their rear ends outside the chambers, oneplunger can bear on both rear ends and push both pistons jointly fartherforwards into their chambers.

In a third aspect, the invention relates to a capsule for two or morecomponents of a material which are to be mixed together, comprising:

-   -   a cartridge comprising an outlet, a first component chamber for        containing a first component, and a second component chamber for        containing a second component, the two component chambers        opening into the outlet; and    -   each of the two component chambers being at least partially        delimited by a foil.

Since each of the two chambers is at least partially delimited by afoil, one plunger can bear against the foil which, upon further advanceof the plunger, is applied against the chamber wall, so that thecomponents enclosed under the foil are squeezed out of the chambers fromthe front in the same way as from a tube.

In a fourth aspect, the invention relates to a capsule for two or morecomponents of a material which are to be mixed together, comprising:

-   -   a cartridge comprising a first component chamber for containing        a first component and a second component chamber for containing        a second component;    -   a housing comprising an outlet and a cartridge chamber for        holding the cartridge, the cartridge chamber being connected to        the outlet;    -   a first piston for movement within the first component chamber,        and a second piston for movement within the second component        chamber.

In a fifth aspect, the invention relates to a capsule for two or morecomponents of a material which are to be mixed together, comprising:

-   -   a first cartridge comprising a first component chamber for        containing a first component, and a second cartridge comprising        a second component chamber for containing a second component;    -   a housing comprising an outlet and a cartridge chamber for        holding the cartridges, the cartridge chamber being connected to        the outlet;    -   a first piston for movement within the first component chamber,        and a second piston for movement within the second component        chamber.

In a sixth aspect, the invention relates to a capsule for two or morecomponents of a material which are to be mixed together, comprising:

-   -   a first cartridge comprising a first component chamber for        containing a first component, and a second cartridge comprising        a second component chamber for containing a second component;    -   a housing comprising an outlet, a first cartridge chamber for        holding the first cartridge, and a second cartridge chamber for        holding the second cartridge, the first and second cartridge        chambers being connected to the outlet;    -   a first piston for movement within the first component chamber,        and a second piston for movement within the second component        chamber.

Preferred features and embodiments of the invention are described in theclaims.

It may be provided that each of the two component chambers is separatedfrom the rest of the interior of the cartridge by a flexible partitionwall.

It may be provided that a common partition wall separates the twochambers from one another.

It may be provided that the partition wall is secured or fixed at leastwith part of its edge on the cartridge, preferably by adhesive bondingor welding, or in one piece therewith.

It may be provided that the partition wall is secured or fixed with therear part of its edge on the front end of the piston, preferably byadhesive bonding or welding, or in one piece therewith.

It may be provided that:

-   -   the cartridge is divided in the axial direction into two shells        for receiving the two components; and    -   each of the two shells is closed off by a foil.

It may be provided that the two shells are connected to one another,preferably by adhesive bonding or welding.

It may be provided that the two shells are connected to one another in afoldable manner at two adjoining edges. The two other edges can havecorresponding locking means.

It may be provided that the two shells are closed off by a common foiland are also connected to one another in a foldable manner.

It may be provided that each of the two chambers is separated from therest of the interior of the cartridge by a rigid partition wall.

It may be provided that a common partition wall separates the twochambers from one another.

It may be provided that the partition wall is secured or fixed at leastwith part of its edge on the cartridge, preferably by adhesive bondingor welding, or in one piece therewith.

It may be provided that the rear end of the partition wall bearslaterally on the allocated piston.

It may be provided that the two pistons are connected fixedly to oneanother at their rear ends, preferably by adhesive bonding or welding,or in one piece therewith.

It may be provided that:

-   -   each chamber is closed off at its rear end by a sealing foil,        preferably by adhesive bonding or welding or hot-sealing; and    -   each piston lies with its front end behind the outer surface of        the allocated sealing foil.

It may be provided that the sealing foil and the allocated piston areconfigured in such a way that the piston, when advanced into thechamber, pierces the sealing foil about its entire circumference.

It may be provided that the sealing foil and the allocated piston areconfigured in such a way that the piston, when advanced into thechamber, pierces the sealing foil only in the area of the cartridgewall. When advanced farther, the piston applies the sealing foil to thepartition wall.

It may be provided that the sealing foil has a predetermined break pointin the area of the cartridge wall and/or the allocated piston has apiercing tip or piercing edge in the area of the cartridge wall.

It may be provided that:

-   -   the cartridge has an interior with a stepped diameter, the front        area being narrower than the rear area;    -   the component chambers are arranged in the front area; and    -   the sealing foil is secured or fixed on the circumferential step        surface, preferably by adhesive bonding or welding or        hot-sealing, and closes off the rear openings of the chambers.

It may be provided that each chamber is closed off at its front end by asealing foil, preferably by adhesive bonding or welding or hot-sealing.

In a first alternative, it may be provided that:

-   -   a first foil at least partially delimits the first component        chamber and separates it from the rest of the interior of the        cartridge; and    -   a second foil at least partially delimits the second component        chamber and separates it from the rest of the interior of the        cartridge.

In a second alternative, it may be provided that:

-   -   a common foil at least partially delimits each of the two        component chambers and separates them from one another;    -   the common foil separates the first component chamber from the        rest of the interior of the cartridge; and    -   a closure means seals the second component chamber off from the        outside.

It may be provided that the closure means is a sealing foil. It may beprovided that the sealing foil closes off the rear opening of thecartridge.

It may be provided that a piston sits at least with its front end in thecartridge, lies with its rear end outside the chambers and, when it ispushed forwards, presses the two components out of their chambers. Itmay be provided that the piston seals the second chamber/cartridge offfrom the outside.

It may be provided that the foil is designed as a leaf and is secured orfixed with its edge on the cartridge, preferably by adhesive bonding orwelding.

It may be provided that the foil is designed as a pouch and its edgesurrounds the outlet opening. The pouch can be a tube which is closedoff at the rear.

It may be provided that the pouch is secured or fixed with at least partof its outer surface on the inner face of the cartridge, preferably byadhesive bonding or welding.

It may be provided that the foil is secured or fixed on the front end ofthe piston, preferably by adhesive bonding or welding.

It may be provided that a sealing foil closes off the rear opening ofthe cartridge.

It may be provided that the sealing foil is designed as a leaf, issecured or fixed with its edge on the edge of the rear opening of thecartridge, and covers the rear ends of the pistons.

It may be provided that the sealing foil is designed as a ring,preferably as a circular ring, or as the jacket surface of a truncatedcone or as the jacket surface of a spherical layer, is secured or fixedwith its outer edge on the edge of the rear opening of the cartridge,and is secured or fixed with its inner edge on the jacket surface and/orrear end of the piston.

It may be provided that a cannula, in which a mixer is arranged, ismounted on the outlet of the cartridge.

It may be provided that the cannula contains means to align the mixer ina defined position or anti-twist means. Preferably one or two pinsarranged in the inner surface of the cannula are used which rotate themixer into a defined position when it is fitted into the cannula.

It may be provided that the outlet of the cartridge is provided withmeans which are used for attachment of a cannula in which a mixer isarranged.

It may be provided that the cannula, in a first position, closes off theoutlet of the cartridge and, in a second position, is connected to theoutlet of the cartridge.

It may be provided that the cannula is mounted pivotably and/ordisplaceably on the cartridge.

It may be provided that the cannula is mounted with a press fit on thecartridge.

It may be provided that the outlet of the cartridge is closed off by astopper. The stopper is pushed forwards out of the outlet when pressureis exerted on the components.

It may be provided that the stopper is connected fixedly to the mixer,preferably by adhesive bonding or welding, or in one piece therewith.The stopper is pushed forwards together with the mixer when pressure isexerted on the components, so that the stopper frees the outlet.

It may be provided that the centre axis of the capsule and of thecannula is curved.

It may be provided that:

-   -   the cartridge has an interior with a stepped diameter, the front        area being wider than the rear area;    -   the chambers are arranged in the front area; and    -   the piston has a jacket surface matching the stepped interior        and sits with its front end in the front area and with its rear        end in the rear area.

It may be provided that the cartridge has a front opening which isclosed off by a cap in which the cannula is mounted.

It may be provided that the capsule has means which are used forcoupling the capsule to an applicator having a single plunger which isadvanced when the applicator is actuated.

It may be provided that the capsule is configured in such a way that itcan be coupled to an applicator having a single plunger which isadvanced when the applicator is actuated.

It may be provided that the two pistons sit with their rear ends in thecartridge when the piston has not yet been advanced or has beenpartially or completely advanced.

In a seventh aspect, this invention relates to a method for dispensing amaterial consisting of two or more components which are to be mixedtogether, said method comprising steps in which:

a) a capsule according to the invention is produced, each componentchamber containing the allocated component;

b) if necessary, a cannula in which a mixer is arranged is attached tothe outlet of the cartridge;

c) an applicator is produced, having:

-   -   a plunger which is advanced when the applicator is actuated, and    -   means which are used for attaching the capsule in such a way        that the plunger can be pushed into the cartridge from the rear;        d) the capsule is attached to the applicator; and        e) the applicator is actuated in such a way that the plunger is        pushed forwards in the cartridge.

By means of the advance of the plunger, the components are pressed outof their chambers through the outlet and into the cannula, and the mixedmaterial is dispensed from the cannula.

In an eighth aspect, this invention relates to a method for producing acapsule according to the invention, wherein each component chambercontains the respective component, said method comprising steps inwhich:

a) the cartridge is produced;

b) the pistons are produced;

c) each component chamber is filled with the respective component;

d) the front portion of each component chamber is closed;

e) a fluid sealant, preferably a hotmelt is filled through the rearopening of each component chamber onto the component already containedtherein;

f) each piston is fitted into the rear opening of each component chamberuntil its front end contacts the sealant or immerges into the still softsealant.

In a ninth aspect, the invention relates to the use of a capsuleaccording to the invention, each chamber containing the allocatedcomponent, with an applicator having:

-   -   a plunger which is advanced when the applicator is actuated, and    -   means which are used for coupling the capsule in such a way that        the plunger can be pushed into the cartridge from the rear.

It may be provided that the material is a material with low to mediumviscosity, preferably a dental impression material or a dental temporaryrestoration material.

It may be provided that the material is a material with high viscosity,preferably a dental filler material.

It may be provided that the material is a material consisting of liquidand/or pasty components.

It may be provided that the two chambers lie next to one another.

The material can be a dental material.

It may be provided that the cartridge is made from a different materialthan the housing.

It may be provided that the cartridge is made from a different materialthan the piston.

It may be provided that the housing is made from a different materialthan the piston.

It may be provided that the first piston is connected to or formed inone piece with the second piston.

It may be provided that at least one of the pistons is connected to orformed in one piece with at least one of the cartridges.

It may be provided that at least one of the component chambers has atleast one opening closed by a seal.

It may be provided that the seal is a film attached to the cartridge.

It may be provided that the seal is formed in one piece with thecartridge.

It may be provided that the seal is a membrane formed in one piece withthe cartridge.

It may be provided that the capsule comprises a piercing member forpiercing the seal.

It may be provided that the first component chamber has a rear openingclosed by the first piston.

It may be provided that:

-   -   the first piston has a front end;    -   the first component chamber has a rear opening for receiving the        first piston;    -   the front end is connected to or formed in one piece with a part        of the cartridge surrounding the rear opening and closes the        rear opening.

It may be provided that the connection between the piston and thecartridge forms a breaking line which enables the parts to bedisconnected upon advancing the piston.

It may be provided that the first component chamber has a rear sectionholding a plug.

It may be provided that the plug is formed in one piece with a part ofthe cartridge surrounding the rear section.

It may be provided that the plug is made from a different material thanthe cartridge.

It may be provided that the plug comprises a through hole running fromthe outside to the inside of the first component chamber.

It may be provided that:

-   -   the plug has a rear face;    -   the plug comprises a filling nipple protruding from the rear        face;    -   the through hole runs through the filling nipple.

It may be provided that the capsule comprises a stopper for closing thethrough hole.

It may be provided that the plug has a front face with a funnel shapedsurface leading to the through hole.

It may be provided that:

-   -   the plug is made from an elastic material;    -   the through hole is collapsed at least when the plug sits in the        first component chamber.

It may be provided that:

-   -   the cartridge comprises an outer wall with a cylindrical outer        surface;    -   the cartridge chamber comprises a cylindrical inner surface        facing the outer surface when the cartridge is held in the        cartridge chamber;    -   a tongue and groove joint is provided on the outer surface and        the inner surface.

It may be provided that:

-   -   the cartridge comprises a partition wall between the first        component chamber and the second component chamber;    -   the groove of the tongue and groove joint runs along the line        where the partition wall meets the outer wall.

It may be provided that at least the outer wall of the cartridge is madefrom a material containing at least one nano filling substance. Forexample, by adding a suitable nano filling substance the oxygenpermeation through the outer wall of the cartridge may be increasedwhile maintaining the water vapor barrier so that an anaerobic oroxygen-free polymerization of a component contained in the componentchamber adjacent this outer wall, may be prevented.

It may be provided that at least the outer wall of the cartridge is madefrom a generally transparent material which is opaque for certain wavelength. One example is a transparent orange material which is opaque forblue light.

It may be provided that:

-   -   at least the first component chamber has a rear section holding        a permeable piston which is permeable to air but impermeable to        the first component;    -   the permeable piston has a front face contacting the first        component contained in the first component chamber.

It may be provided to use a ball, especially an elastic ball (e.g. madeout of rubber) as piston. A ball may provide optimum sealing as well asadvantages during assembly (no correct positional arrangementnecessary). Furthermore a ball provides an enforcement of the sealingwhen pushed by the plunger, as it is compressed in length and thereforeincreases in diameter thus enforcing the contact pressure of thesealing.

It may be provided that the capsule comprises a snap-fit lock to ensurethat the cartridge does not migrate rearwards when the paste isdispensed (since paste can flow under the cartridge at the end). Forexample, locking hooks can be arranged on the inside of the capsule andsnap into corresponding catches on the cartridge as soon as thecartridge is pressed into its front end position. A bayonet-type closurecould also be provided between cartridge and capsule.

It may be provided that the capsule contains a pre-mixing chamber which,before the two substance components A and B flow into the static mixer,divides them into several, e.g. four, paste streams A, B, A, B andbrings these back together to form two paste streams, which however eachconsist of at least two different substance components A and B. This canbe achieved by each substance component, even as it flows out of thecapsule, being divided into two or more paste streams which are thenconveyed farther on the capsule end face through a type of labyrinth andare brought together in the above-described manner. The advantage ofthis is that a pre-mixing chamber cuts down the overall structurallength, because the actual static mixer in the cannula can be suppliedwith already pre-mixed substance and can therefore be made shorter.

It may be provided that substances with nanofillers are used for makingthe cartridge, e.g. in order to increase the storage stability of thefilled substances. For example, addition of nanofillers can increaseoxygen permeation through the cartridge wall (e.g. to prevent anaerobicor oxygen-free polymerization of the component adjacent this cartridgewall), while the water vapor barrier is maintained. It is also possibleto use plastics and appropriate additives with which thin walls can beinjection-molded or with which the opacity of the cartridge can beincreased (less protection against light in production).

It may be provided that the component chambers have equal or differentcross sections, with respect to both the shape and the size.

It may be provided that the capsule is adapted for use with anapplicator having a single plunger.

It may be provided that the cartridge comprises at least two pistons formovement within respective component chambers, wherein each piston has arear face, wherein the rear faces are adapted to be simultaneously incontact with a single plunger.

It may be provided that the cartridge or the housing comprises connectorelements fitting to corresponding connector elements of an applicator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional side view of a capsule in a first embodiment;

FIG. 2 is a sectional front view of a capsule in a second embodiment,having a divided cartridge;

FIG. 3 is a sectional side view of a capsule in a third embodiment;

FIG. 4 and FIG. 5 are perspective views and sectional views of a capsulein a fourth embodiment;

FIG. 6 is a sectional side view of a capsule in a fifth embodiment;

FIG. 7 a sectional side view of a mixer with stopper as closure for thechamber outlets;

FIG. 8 is a sectional side view of two variants of a sealing foil at therear opening of the cartridge;

FIG. 9 is a sectional side view of a cartridge with stepped interiorwider at the front;

FIG. 10 is a sectional side view of a cartridge with stepped interiornarrower at the front;

FIG. 11 is a sectional side view of another cartridge with steppedinterior narrower at the front;

FIG. 12 is a sectional side view of a further cartridge with steppedinterior narrower at the front;

FIG. 13 is a sectional side view of a capsule in a sixth embodiment,having a housing holding the cartridge;

FIG. 14 is a perspective view of a cartridge for the capsule of FIG. 13;

FIG. 15 is a sectional side view of a capsule in a seventh embodiment,having piercing elements;

FIG. 16 is a sectional side view of piercing elements in two variantswith an internal channel;

FIG. 17 is a sectional side view of an assembly of cartridge andpistons;

FIG. 18 is a sectional side view of another assembly of cartridge andpistons;

FIG. 19 is a sectional side view of a further assembly of cartridge andpistons;

FIG. 20 to FIG. 22 are sectional side views of a cartridge with plugs;

FIG. 23 is a sectional side views of plugs with conical ends;

FIG. 24 is a sectional side views of a plug with a stopper;

FIG. 25 and FIG. 26 are perspective views of other cartridges with agroove;

FIG. 27 is a sectional side view of a further cartridge and a sinteredpiston;

FIG. 28 is a sectional side view of other sintered pistons;

FIG. 29 and FIG. 30 are sectional side view of a capsule in a seventhembodiment;

FIG. 31 and FIG. 32 are sectional side views of a cartridge beingfilled;

FIG. 33 is a sectional side view of a cartridge having pistons withinclined air vent channels;

FIG. 34 is an exploded view of a capsule having a substantially squarecartridge;

FIG. 35 is a sectional side view of a capsule in which a cartridgereplaces the housing;

FIG. 36 is a cross-sectional view of a cartridge having chambers;

FIG. 37 is a schematic illustration of pistons molded directly onto asealing foil;

FIG. 38 is a sectional view of an alternate cartridge having a partitionwall separating adjacent component chambers;

FIGS. 39-42 are sectional side views of a cartridge that may beassociated with air-free filling of the substance;

FIGS. 43-47 are sectional view of a cartridge which can be sealed atboth ends;

FIGS. 48-58 are cross-sectional side views of an alternative cartridgeand piston arrangement;

FIG. 59 and FIG. 60 are exploded views of a capsule having a pivotingcannula;

FIG. 61 is a cross-sectional elevated side view of a capsule having apivoting cannula;

FIG. 62 is a front view of a cartridge having channels;

FIG. 63 is a top view of a seal;

FIGS. 64 and 65 are cross-sectional side views of alternativetwo-component cartridge assemblies;

FIGS. 66-68 are cross-sectional side views of a capsule having asnap-fit connection;

FIG. 69 and FIG. 70 are side views of dispensing applicators;

FIGS. 71-74 are cross-sectional side views of a capsule with stationarypiston and one-piece piston assembly;

FIG. 75 is an elevated cross-sectional side view of a capsule havingpiercing elements; and

FIG. 76 is a cross-sectional side view of a cartridge affixed by fixingelements.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the invention are described in more detailbelow with reference to the attached drawings, which are by way ofexample only.

FIG. 1 shows a capsule 10 in a first embodiment, comprising:

-   -   a cartridge 11 comprising an outlet 12, a first component        chamber 13 for containing a first component, and a second        component chamber 14 for containing a second component, the two        chambers opening into the outlet 12; and    -   a piston 15 which at least with its front end sits in the        cartridge 11, lies with its rear end outside the component        chambers 13, 14 and, when it is pushed forwards, presses the two        components out of their component chambers 13, 14.

Each of the two component chambers 13, 14 is separated from the rest ofthe interior of the cartridge 11 by a common partition wall 16 which isflexible and separates the two chambers from one another. The partitionwall 16 is fixed with the rear part of its edge on the front end of thepiston 15, and with the remaining part of its edge on the cartridge 11.The partition wall is secured or fixed at least with part of its edge onthe cartridge, preferably by adhesive bonding or welding, or by being inone piece therewith.

A cannula 21, in which a mixer 22 is arranged, is mounted on the outlet12 of the cartridge 11.

FIG. 2 shows a capsule 10 in a second embodiment in which:

-   -   the cartridge 11 is divided in the axial direction into two        shells 18 for receiving the two components; and    -   each of the two shells 17 is closed off by a common foil 18.

The two shells 17 are connected to one another in a foldable manner attwo adjoining edges. The two other edges can have corresponding lockingmeans (not shown).

FIG. 3 shows a capsule 10 in a third embodiment similar to the firstembodiment, and the differences will be described in the following.

This capsule 10 comprises:

-   -   a first piston 19 which at least with its front end sits in the        first component chamber 13, and a second piston 20 which at        least with its front end sits in the second component chamber        14, which two pistons lie with their rear ends outside the        component chambers and, when they are pushed forwards, press the        two components out of their component chambers.

The common partition wall 16 is rigid and has as can be seen in theupper picture of FIG. 3, a free rear end or edge 23 which sits betweenthe facing sides of the pistons 19, 20 so that it bears laterally onthem. The remaining part of the partition wall's 16 edge is in one piecewith the cartridge 11.

The two pistons 19, 20 are connected fixedly to one another at theirrear ends and are in one piece with each other.

FIG. 4 and FIG. 5 show a capsule 10 in a fourth embodiment similar tothe third embodiment, and the differences will be described in thefollowing.

The cannula 21 is mounted pivotably on the cartridge 11 in such a mannerthat the cannula 21, in a first position (FIG. 4), closes off the outlet12 of the cartridge 11 and, in a second position (FIG. 5), is connectedto the outlet 12 of the cartridge 11.

FIG. 6 shows a capsule 10 in a fifth embodiment similar to the aboveembodiments, and the differences will be described in the following.

A first foil 24 delimits the first component chamber 13 and separates itfrom the rest of the interior of the cartridge; and a second foil 25delimits the second component chamber 14 and separates it from the restof the interior of the cartridge. The piston 15 sits with its front endin the cartridge 11 and lies with its rear end outside the componentchambers 13, 14. Each foil 24, is designed as a leaf and is secured orfixed with its edge on the cartridge 11, preferably by adhesive bondingor welding.

FIG. 7 shows a front portion of the cartridge 11 and a rear portion ofthe cannula 21 and mixer 22. The outlet of the cartridge 11 comprisestwo outlet openings 12 of the component chambers 13, 14, which areclosed off by two stoppers 26 respectively (upper picture). The stoppers26 are in one piece with the rear portion of the mixer 22 and are pushedforward together with the mixer 12 (lower picture) when pressure isexerted on the components, so that the stoppers 26 free the outletopenings 12.

FIG. 8 shows very schematically (e.g. the outlet 12 and the componentchambers 13, 14 are not shown) two variants of a sealing for the capsule10. In both variants, a sealing foil 27 closes off the rear opening ofthe cartridge 11 and is secured or fixed with its outer edge on the edgeof the rear opening of the cartridge 11. Although FIG. 8 shows veryschematically only one piston 15, this one is to be understood torepresent also the two pistons 19, 20.

In the first variant (upper half of FIG. 8) the sealing foil 27 isdesigned as a leaf and covers the rear end of the piston 15.

In the first variant (lower half of FIG. 8) the sealing foil 27 isdesigned as a circular ring and is secured or fixed with its inner edgeon the jacket surface of the piston 15.

FIG. 9 shows a cartridge 11 similar to that shown in FIG. 1, but havingan interior with a stepped diameter, the front area being wider than therear area. The component chambers 13, 14 are arranged in the front area,and the piston 15 has a jacket surface matching the stepped interior andsits with its front end in the front area and with its rear end in therear area.

FIG. 10 shows a cartridge 11 similar to that shown in FIG. 3, but havingan interior with a stepped diameter, the front area being narrower thanthe rear area. The component chambers 13, 14 are arranged in the frontarea, and a sealing foil 28 is secured or fixed on the circumferentialstep surface and closes off the rear openings of the component chambers13, 14. The sealing foil 28 and the pistons 19, 20 are configured insuch a way that each piston 19, 20, when advanced into the allocatedcomponent chamber 13, 14, pierces the sealing foil 28 about the piston's19, 20 entire circumference.

FIG. 11 shows a cartridge 11 similar to that shown in FIG. 10. Eachpiston 19, 20 has a piercing tip or piercing edge 29 in the area of thecartridge wall. The sealing foil 28 and the pistons 19, 20 areconfigured in such a way that each piston 19, 20, when advanced into theallocated component chamber 13, 14, pierces the sealing foil 28 only inthe area of the cartridge wall. When advanced farther (right picture),the pistons 19, 20 push the sealing foil 28 toward the partition wall16.

FIG. 12 shows a cartridge 11 and pistons 19, 20 similar to those shownin FIG. 10. Each component chamber 13, 14 is closed off at its front endby a sealing foil 30 that breaks (right picture) when the pistons 19, 20are advanced into the component chambers 13, 14.

FIG. 13 and FIG. 14 show a capsule 10 in a sixth embodiment, comprising:

-   -   a cartridge 11 comprising a first component chamber 13 for        containing a first component and a second component chamber 14        for containing a second component;    -   a body or housing 31 comprising an outlet 12 and a cartridge        chamber 32 for holding the cartridge 11, the cartridge chamber        32 being connected to the outlet 12;    -   a first piston 19 for movement within the first component        chamber 13, and a second piston 20 for movement within the        second component chamber 14.

The body or housing 31 (FIG. 13) is a hollow cylinder (without partitionwall) for receiving a two-chamber or multi-chamber container orcartridge 11 in the cartridge chamber 32 (FIG. 14), the capsule 10 thusbeing in two parts. It is advantageous here that the container orcartridge 11 can be designed to permit optimal aging stability of thepastes, while the capsule 10 and/or the housing 31 includes furtherfunctional elements.

The container used is preferably a cylindrical cartridge 11 (FIG. 14)with two or more channels or chambers 13, 14 which are arranged on thelongitudinal axis of the cylinder and receive the pastes. Optionally, itis possible to use an individual cartridge for each paste component.This provides advantages in manufacturing pastes with several colourshades: one component contains the different shades, while the otheralways has the same composition and can be produced in larger batches.

It is also advantageous that the cartridge 11 can be made of a materialwhich is optimized in respect of the storage of the substance with whichit is filled, while the housing 31 can be configured with design orlabeling requirements in mind. For example, the housing 31 can becolour-coded depending on the type of filling material (e.g. a fillingmaterial for different tooth colours). The cartridge 11, however, can bemade of the same material for all substance types, e.g. can betransparent in order to avoid colour penetration into the substance withwhich it is filled. Or it can be made of dark material in order to takeaccount of the photosensitivity of the substance with which it isfilled.

A cartridge 11 designed in this way can be easily sealed off with foils28, 30 at its ends (lower picture in FIG. 13).

Instead of the sealing foil 28 on the cartridge's 11 rear end, this rearend can be closed off with a membrane formed integrally with thecartridge 11 (e.g. injection-molded).

FIG. 15 shows a capsule 10 in a seventh embodiment similar to the sixthembodiment, and the differences will be described in the following.

The arrangement of the housing 31 receiving the cartridge 11 affords inparticular the possibility of a self-opening mechanism for the front endof the cartridge 11. For example, as shown in FIG. 15, the inside of thehousing 31 can have piercing elements 33 for the cartridge 11. When theplunger 63 of the applicator 62 presses on the pistons 19, 20, saidpistons 19, 20 are moved together with the cartridge 11 towards thepiercing elements 33, whereupon the front foil 30 is punctured. Thepiercing elements 33 can effect initial piercing of the foil 30, so thatthe foil 30 tears as the paste is advanced.

The piercing elements 33 are here connected to the housing 31, but itmay also be provided that they are formed integrally therewith orconnected to or formed integrally with the mixer 22 and/or the cannula21.

FIG. 16 shows two variants of piercing elements 33 with an internalchannel 34 through which the pastes flow forwards to the cannula 21.

FIG. 17 shows a cartridge 11 and pistons 19, 20 similar to those shownin FIG. 13, but forming together an assembly by being formed integrallywith each other. This assembly may for example also be achieved byforming them in a two-component injection-molding process.

Here, the connection 35 between cartridge 11 and each piston 19, 20 isdesigned such that it ruptures when the respective piston 19, 20 isadvanced. This can be achieved by making the connection 35 between therespective parts very thin, e.g. the pistons 19, 20 can be connected tothe chambers 13, 14 only at the edges of these parts.

FIG. 18 shows another assembly of cartridge 11 and pistons 19, 20similar to that shown in FIG. 17, but here the front portion of thepistons 19, 20 has a different shape as shown.

FIG. 19 shows a further assembly of cartridge 11 and pistons 19, 20similar to that shown in FIG. 18, but here the parts 11, 19, 20 areconnected to one another by a thin membrane 36.

With a predetermined breaking point of suitable design, this breakingpoint could be used to advantage. If pistons 19, 20 and cartridge 11 areconnected to one another via a thin membrane 36, the latter is expandedbefore breaking, so that the shape of the membrane 36 is slightlygreater than the cross section of the chambers 13, 14. In this way, themembranes 36 act as sealing elements when the pistons 19, 20 areadvanced. The sealing effect can also be assisted by suitable shaping ofthe membrane 36, e.g. as an umbrella or circular lip seal in such amanner that the sealing effect increases with increasing pressure.

FIG. 20 to FIG. 22 show a cartridge 11 provided with detachableclosures, e.g. plugs 37. The plugs 37 have filling nipples 38 extendingfrom their rear faces, and are preferably formed integrally with thecartridge 11. A through-bore 39 allows the cartridge 11, already sealedat the front end by foil 30, to be filled via the plugs 37, e.g. byimmersion filling, the metering or filling needles 40 (FIG. 21) lying atthe filling level of the substance used for filling, i.e. firstcomponent 41 and second component 42. Vacuum filling can alternativelybe used instead of immersion filling.

After the filling procedure, the filling nipples 38 are closed off (FIG.22), e.g. by squeezing with heated or unheated tools. The squeezing canbe done using tools with two, three or more jaws. This ensures that thefilling procedure is carried out free from air bubbles. Instead ofsqueezing, it is also possible to seal the filling nipples 38 by a (e.g.heated) wire loop, so that, instead of a wide seal seam, a substantiallyround pressing is obtained. Alternatively, the filling nipples 38 can beclosed by twisting them. The nipples 38 are preferably heated for thispurpose. Sealing would also be possible if the inner surface of thenipple 38 is contaminated with paste (depending on the filled paste).

FIG. 23 shows plugs 37 that are made conical at the end so that thefilled substance can flow without forming air inclusions.

In one option, the cartridge 11 can be made of elastic material, andthus the nipple 38 too can be made elastic. It is advantageous that theclosures 37 do not have to be provided with open through-bores 39, butcan be punctured with pointed filling needles 40. After removal of thefilling needles 40, the openings 39 close automatically. It is alsopossible for the cartridge 11 to be injection-molded from rigid materialand for the closures 37 to be injection-molded from elastic material inthe two-component injection-molding process.

Another option is for the cartridge 11, unsealed at the front, to befilled from the front end. In this case, openings are not necessary inthe closures 37. After the cartridge 11 has been filled, it is closed bya thermally applied, e.g. heat sealed, sealing foil 30 or by an adhesivesealing foil 30.

FIG. 24 shows a plug 37 in the first component chamber 13. Instead ofsealing the closure nipple 38, here the filling bore 39 is closed with astopper 43. The stopper 43 can contain an overflow volume 44 (cf. rightstopper) so that, when pressed into the filling bore 39, it displacessubstance, which is taken up by the overflow volume 44, and thus closesfree from air. It is possible to seal the stopper 43, e.g. byultrasound. For ultrasonic welding, it is possible to provide energyflow directors 45 in the form of bulges or ridges (cf. left stopper).

FIG. 25 and FIG. 26 show two further variants for the cartridge 11. Inorder to orient the cartridge 11 in the housing 31, the cartridge 11 canbe provided with at least one notch or groove 46, preferably along theline nearest to the partition wall 16 on the outer wall or shell of thecartridge 11. It is advantageous here that the natural sink marks (FIG.25) arising in the injection-molding process can simultaneously beavoided or used as positioning groove 46. Moreover, by arranging thegroove 46 in the area of the partition wall 16, influences on thepermeation properties of the cartridge 11 are substantially avoided.Optionally, it is possible to provide just one groove 46 (FIG. 26),resulting in a more distinct orientation of the cartridge 11 withrespect to the housing 31. Alternatively, a raised bridge or key can bearranged on the cartridge 11. Both bridge or key and groove 46 canextend along the entire length of the cartridge 11 or only along part ofits length. The housing 31 has the geometrical counterpart which engagesin the groove 46 of the cartridge 11 or which receives the bridge or keyon the cartridge 11.

FIG. 27 shows a cartridge 11 having the chambers 13, 14 sealed at oneend (by foil 30) and filled to a defined level and then closed withpistons 19, 20. This permits an air-free filling of the cartridge 11.The pistons in this case are designed to be air-permeable, so that theair can escape, while the pistons are pushed into the chambers andtherefore no air is trapped in the chambers. The pistons are on theother hand configured in such a way that they are impervious to thepaste located in the chambers. Possible solutions in this respect arepistons made of sintered materials, open-pore foams, or small openingsin the pistons.

After fitting the pistons, the cartridge is sealed (by foil 28) in orderto ensure the necessary storage stability.

If the filled substances require oxygen during storage, the chambers canbe extended in length so that a hollow space 47 is obtained between therear end of the piston 19, 20 and the sealing foil 28.

Optionally, sintered pistons 19, 20 can be combined with the hotmeltsealing principle. In a preferred embodiment shown in FIG. 28, thepistons 19, 20 are only partially porous, as shown at the porous sinterpart 49, and have channels 49 for injection of a sealing material(hotmelt 64). Such pistons can be produced for example by compaction ofthe sintered material 48 (optionally under the action of heat), bytwo-component injection-molding, or by foils sealed on at the ends.After the pistons have been fitted into the chambers 13, 14 filled withdental substance, these are sealed off by injection of the sealingmaterial. During fitting of the pistons, the channels 49 are still open,so that when the pistons are moved into the chambers, the displaced aircan escape through the porous sinter layer 48 and the channels 49.

FIG. 29 and FIG. 30 show a capsule 10 in a seventh embodiment,comprising a cartridge 11 having a front or container part 11′ and arear or piston part 11″, and further comprising a hinge 50 connectingthese parts 11′, 11″. This permits a stepped capsule design (smalldiameter at the rear portion of piston part 11″ for receiving it in anapplicator 62 (FIG. 69, FIG. 70), large diameter at container part 11′for increasing the filling volume). Further, a sealable part, i.e. therear face of the chamber part 11′ which is closed off with sealing foil28, is obtained, but the capsule 10 can be injection-molded in one tool.In addition, the capsule 10 is provided with a second hinge 51connecting the container part 11′ with the cannula 21, and like the rearface of the container part 11′, the front face of the chamber part 11′too may be closed off with sealing foil 30.

The hinge parts 21, 11′, 11″ are mounted via non-releasable lockingelements 52, preferably two, three or more, arranged on thecircumference of the capsule 10.

In general a stepped capsule design with or without hinge option can beused to increase the filling volume of the capsule. In this case therear end of the capsule, i.e. the rear portion of piston part 11″, whichis designed for adapting to an applicator 62 (FIG. 69, FIG. 70), is keptunmodified while the diameter of the container part 11′ of the capsulecan be increased as needed.

Immersion Filling Through Pistons (FIG. 31 and FIG. 32)

To fill the cartridge 11, the pistons 19, 20 can first be pushed intothe chambers until they reach their front end position. The fillingneedles 40 are then guided through the pistons 19, 20 (FIG. 31). Duringfilling, the pistons are pushed back by the paste pressure and thefilling needles are guided back mechanically (principle: immersionfilling) (FIG. 32). In this way, inclusion of air in the chambers isavoided. The pistons are preferably made of an elastic material (e.g.rubber), the filling needles piercing through the pistons. After thefilling procedure, the filling needles are pulled out, by which meansthe paste, because of the elastic properties of the piston material, isstripped off from the filling needles. The openings also closeautomatically because of the elastic properties of the piston material.Nevertheless, the cartridge can be sealed if required, the pistons thenalso being sealed in. It is in turn possible to provide an air volumebetween sealing foil and the pistons.

Alternatively, the pistons can be made of less elastic material and canbe provided with bores.

Filling from Front End

It is possible for the cartridge/capsule to be filled from the substanceoutlet end. In this case, it is recommended to fit the pistons inadvance (pistons pushed forwards completely). The pistons are thenpressed back during filling, if appropriate to a limit stop, so that thechambers are free from air. In this solution too, it is possible tocreate an air volume behind the pistons if the cartridge/capsule islonger than is necessary for the filling volume and is sealed at bothends.

Air Cushion at Front End of Cartridge/Capsule

It is possible for the cartridge, sealed at one end, to be filled byimmersion filling, but not to the brim, and then to seal the second end.The air then enclosed remains at the second end when the filledsubstances have a high viscosity. If the cartridge is arranged with the“air side” forwards in the capsule, the air is first pressed out whenthe substance is applied. The substance is then dispensed in exactproportion.

Pistons with Inclined Bore (FIG. 33)

A further possibility for air-free filling is provided by pistons 19, 20with inclined air vent channels 66 (FIG. 33). The channels 66 extendfrom the front end of the piston 19, 20 to the outer wall or shell ofthe piston. When the pistons are pressed into the chambers 13, 14, thefilled substance can escape outwards through the channels. The piston issealed off only when it has been pressed in so far that the opening onthe shell is located in the chamber. Excess substance can then either besuctioned off or stripped off from the opening. The piston canoptionally be pressed still farther into the chamber if the sealing foilis slightly elastic or thermoformed to provide the necessary volume forthis.

Optimizing Volume (FIG. 34-FIG. 36)

In an optional variant, the cartridge design deviates from the roundshape. In this way, the housing 31 is only partially weakened, insteadof the whole wall of the housing 31 being made thin. The aim here is tomaintain sufficient mechanical strength of the capsule 10, while theinternal volume is increased. Such a solution may be achieved with asubstantially square cartridge 11 (FIG. 34). In the area of thecartridge corners, the housing 31 is weakened or broken through,whereas, in the area of the cartridge sides, the capsule wall consistsof thick-walled bridges. These bridges take up the application forcesduring use of the capsule. Optionally, the cartridge 11 can alsocompletely replace the housing 31 (FIG. 35).

In a further design for optimizing the volume of the capsule, thecapsule is made wider (FIG. 36). The U-shaped applicator can still beused.

In-Mould Decoration Technique for Assembly of Parts (FIG. 37)

It may be provided, for example, to injection-mould the pistons 19, 20directly onto the sealing foil 28 and to use the foil 28 at the sametime as a transporter for handling the component parts

Air Gap as Diffusion Barrier (FIG. 38)

It may be provided that a partition wall 16 between two adjacentcomponent chambers 13, 14 is designed as a double wall (FIG. 38) inorder to reduce permeation of substances between the two chambers 13,14.

Integral Piston with Hotmelt Closure (FIG. 39-FIG. 42)

A preferred solution for air-free filling of the substance isillustrated in FIG. 39 to FIG. 42. The cartridge 11 and the pistons 19,20 are formed in one piece (FIG. 39). Between cartridge 11 and pistons19, 20 there are predetermined breaking points 35 (FIG. 40) which breakupon a defined axial loading of the arrangement. The pistons 19, 20 havean external dimension and shape corresponding approximately to theexternal dimension/shape of the chambers 13, 14 in the cartridge 11. Attheir front ends, the pistons 19, 20 preferably have a bead or bulge 67(FIG. 40) which is slightly overdimensioned in relation to the chambers,while the remaining length of the piston has a slight underdimension(clearance) relative to the chambers.

For filling the piston/cartridge arrangement, the cartridge is sealedoff at the front with a foil 30. The substance 41, 42 is then introducedthrough the filling bores or channels 49 by means of immersion filling,starting from the sealing foil 30 and in the direction of the mouth orinner cone of the filling bores or channels 49. The filling level ispreferably such that the substance 41, 42 reaches into the mouth orinner cone area of the filling bores or channels 49 (FIG. 41). In afurther step, the filling bores or channels 49 are then closed off witha material that can harden (e.g. hotmelt material 64).

The advantage of this method is that filling tolerances of the substanceplay no role in relation to air-free filling and in relation to exactlyproportioned dispensing of the substance by the customer.

In order to ensure optimal stability of the hotmelt closure, the fillingbores in the mouth or inner cone area to the cartridge are equipped witha double cone shape. This ensures that the “hotmelt stopper” 64 (FIG.41) seals by shrinking and that, in the event of excess pressure or lowpressure, cannot come loose in the cartridge (e.g. through temperaturefluctuations).

The pistons 19, 20 are preferably designed conically or sloping in atthe end towards the filling bores or channels 49 (FIG. 42) in order toavoid air inclusions during the immersion filling.

Cartridge which can be Sealed at Both Ends (FIG. 43-FIG. 47)

With the solution shown in FIG. 43 to FIG. 47, a cartridge 11 can befilled free from air and can be sealed without appreciable airinclusions. In this case, the component chambers 13, 14 have, at leastat one end, a narrowing cross section (FIG. 43 and FIG. 47) whichcreates an enlarged sealing surface on the end face of the cartridge 11(the narrowing cross section will be arranged to the front end side ofthe housing 31 as the pistons can only penetrate the cartridge from theopen side—as an option the cartridge 11 may be arranged in the oppositeorientation if it is used together with the embodiment shown in FIGS. 71and 72). In the filling procedure by means of immersion filling (FIG. 44and FIG. 45), the minimum filling level is flush with the end face ofthe cartridge (right picture of FIG. 45), with filling tolerances givinga slight excess. The enlarged sealing surface has the effect that thepossible excess, upon application of the sealing foil 30, wets only avery small part of the sealing surface and, together with the rest ofthe sealing surface, leads to a safe and air-free sealing (FIG. 46).

To fill the cartridge flush with the end face, the filling needles 40are arranged sealingly in the filling openings so that the air displacedduring the filling procedure can escape, whereas the paste cannot easilypass through the gap between the two parts. This results in an abruptpressure increase in the filling unit as soon as the paste reaches theend of the narrowed chamber area. This pressure increase can be detectedby the filling unit, and the filling procedure can thus be automaticallyended with precision.

Alternatively, filling can be made flush with the end face by placingthe filling needle on said end face of the cartridge, but not into thesealing area.

A combination solution can be provided in which the aforementionedpiston with hotmelt closure is arranged at one end of the cartridge andthe narrowed area at the other end. This affords advantages in terms ofsealing at the front end (larger sealing surface) and one-pieceproduction of the cartridge and of the piston. A preferred productionmethod for this is injection blow molding and subsequent formation ofthe narrowing because of the difficulty in removing the cartridgeinterior from the mould.

Sealing the Pistons by Means of Sealing Material (Hotmelt) (FIG. 48-FIG.58)

In one embodiment, the pistons 15, 19, 20 are provided with channels 49through which a sealant 64 (hotmelt, adhesive, etc.) can be injected.The pistons can first be fitted after the cartridge 11 has been filledwith paste 41, 42, and they can then be sealed off by injecting thesealant. It is advantageous here that the paste can thus be enclosedfree from air in the chambers.

In a first variant of the solution (FIG. 48 and FIG. 49), the pistons15, 19, 20 have an annular groove into which sealant 64 can be injectedvia a filling channel 49. A seal is thus created between the piston andthe inside wall of the chamber. The adhesive is preferably chosen suchthat it flows easily onto the surface of the chamber and such that itdoes not form a firm attachment but instead only adheres to the surface.In this way it is possible to move the piston in order to dispense thepaste, the sealing material then detaching from the chamber wall(adhesion break) and furthermore acting as a sliding seal. Optionally,the adhesive can be chosen such that it forms a firm connection with thepiston and the chamber wall, but itself has a relatively low strengthand tears upon displacement of the piston (cohesion break).

Optionally, the sealing material 64 can also be injected through afilling channel in the capsule wall (FIG. 50 and FIG. 51).

In a second variant (FIG. 52 and FIG. 53), after the piston has beenfitted, a hollow space remains between the paste and the end face of thepiston (FIG. 52). The filling channel 49 is designed in such a way that,upon injection of the sealing material 64, this space is filled withsealing material and thus provides a stopper-shaped sealing of thechamber (FIG. 53). The annular groove illustrated is optional and servesfor further anchoring of the piston or for creating an additionaldefined seal.

In a third variant (FIG. 54 to FIG. 56), the chamber filled with paste(FIG. 54) is closed off with sealing material, e.g. hotmelt 64, (FIG.55) and the piston is then fitted into the still soft sealing material(FIG. 56). In this process, the piston does not pass through the sealingmaterial layer. In this way, a simple air-free closure is obtained.Closure of a two-chamber capsule affords the added advantage that thefilling level of the paste does not have to be exactly the same in bothchambers and the filling level of the sealing material also does nothave to exactly correspond. The piston is configured in such a way thatexcess sealing material can escape in a riser tube arranged in thepiston (FIG. 56).

Alternatively, the cooled sealing material could itself serve as astopper. In this case, the piston would not be pressed into the softsealing material. The piston would then only be used for transmittingforce for advancing the piston.

In a fourth variant (FIG. 57 and FIG. 58), the piston itself has sealingfeatures (e.g. sealing beads or bulges). In this variant, the chamber ispreferably filled from the front end of the capsule (FIG. 57), thepiston being pushed or drawn back with the paste filling level. In theend position of the piston (FIG. 58), the latter is then fixed andsealed off by a sealing material according to one of the abovementionedmethods.

FIG. 59 to FIG. 63 show a capsule 10 in an eight embodiment and relatedparts thereof.

FIG. 59 to FIG. 61 show the capsule 10 comprising the cartridge 11, thepistons 19, 20, the pivoting cannula 21, and a cap 53 for affixing thecannula 21. FIG. 59 shows the capsule 10 before fitting the cap 53, andFIG. 60 shows the capsule 10 after fitting the cap 53. FIG. 61 shows alongitudinal section through the first component chamber 13 and firstpiston 19. Here, the component chambers 13, 14 and the pistons 19, 20each have circular cross sections. The pistons 13, 14 are connected attheir back ends to a connecting piston having a circular cross sectionof larger diameter fitting to the diameter of the plunger 63 of anapplicator 62 (FIG. 69, FIG. 70).

FIG. 62 shows the front end of the cartridge 11 having channels whichare filled with sealing material after the pivoting cannula 21 has beenfitted.

A preferred solution for encapsulating the materials in the cartridge 11and to keep them apart from one another is to close the rear end of thecomponent chambers 13, 14 by plugging with the pistons 19, 20 whereaso-rings mounted on the pistons 19, 20 are used as seals. The front endsof the chambers are closed by the rotatable nozzle or cannula 21 whichacts as a valve. As a seal, o-rings are used or a customized rubber seal60 as shown in FIG. 63.

In an optional preferred solution, hotmelt sealing is used, e.g. asdescribed with respect to FIG. 48 to FIG. 58. In these eightembodiments, it is preferred that in a first step the component chambers13, 14 are filled with the respective components (FIG. 54). In a secondstep the component chambers 13, 14 are closed off with hotmelt 64 (FIG.55). In a third step the piston 19, 20 is fitted into the still softsealing material in a way that it does not pass the sealing materiallayer (FIG. 56).

Two-Component Injection-Molding with Possibility of Mixer Assembly (FIG.64)

The embodiment shown in FIG. 64 permits production of the cartridge 11or housing 31 with pivoting cannula 21 in the two-componentinjection-molding process, the pivoting cannula 21 preferably beingmolded first, then the cartridge 11 or housing 31, and the pivotingcannula 21 being encapsulated by the cartridge 11 or housing 31 so thatthe chambers arranged in the cartridge 11 and intended to receive thedental substance are closed off tight at the cannula side. The plasticsused for both parts and the process parameters in the injection-moldingprocedure are chosen so that, after production, a press-fit between bothparts is obtained, and preferably the surfaces of both parts form adetachable connection (light adhesion). The cartridge 11 or housing 31is thus sealed off tight in the storage condition. Opening of thecartridge 11 or housing 31 is possible, however, by pivoting the cannula21.

Examples of suitable plastics for the proposed technique arepolyolefins, preferably polypropylene, for both parts.

A bore arranged in the cartridge 11 or housing 31 allows the mixer 22 tobe fitted on the already injection-molded cartridge 11 or housing 31.

Two-Component Assembly Injection-Molding with AdditionalInjection-Molded Sealing (FIG. 65)

In the embodiment shown in FIG. 65, cannula and cartridge are producedin a two-component injection-molding process, but without sealing of thesubstance chambers (assembly injection molding).

Between pivoting cannula and the outlet channel of the cartridge, ahollow space remains which can later be filled with a sealing material.After production, the cartridge is preferably first filled with thedental substance and then closed by injection of the sealing material(e.g. as shown in FIG. 48 to FIG. 56). During the filling of thecartridge with dental substance, the unsealed cartridge end (dependingon the filling method) can be used to remove air (FIG. 48 to FIG. 56).

Fitting Cannula with Optional Sealing by Over-Molding (FIG. 66-FIG. 68)

A further possibility for producing the capsule with cannula lies in theformation of a snap-fit connection. The two parts are injectedseparately and are interlocked in a non-releasable manner by means of asnap-fit connection (FIG. 66 and FIG. 67). It order to ensure a securefit when the snap-fit connection is loaded, the elastic components canbe over-molded (FIG. 68). This can also be done so as to seal thecapsule at the same time (not illustrated).

Capsule with Stationary Piston and One-Piece Piston Assembly (FIG.71-FIG. 74)

The capsules 10 in the embodiments shown in FIG. 71 to FIG. 74 provide away to store, static mix and directly deliver the mixed material. Thepiston assembly 54 is one piece with breakable seals 55 between theinner pistons 56 and the outer pistons 57.

The capsule 10 in the embodiment of FIG. 71 and FIG. 72 is placed in adispensing gun or applicator 62 (FIG. 69, FIG. 70) and when actuatedpushes on the inner piston 56. The capsule seal opens when the seal ofthe outer piston 57 contacts the stationary capsule piston 58. As theinner piston 56 is pushed in, the pastes are pushed out into the staticmixer and mixed for delivery out the tip 21.

The capsule 10 in the embodiment of FIG. 73 and FIG. 74 is placed in adispensing gun or applicator 62 (FIG. 69, FIG. 70) and actuated whichpushes in the piston assembly 54. The inner piston 56 moves the outerpiston 57 in until the seals 30 are opened when it contacts thestationary capsule piston 58. The lock 59 disengages the inner piston 56from the outer piston 57 when the inner piston 56 travels to theunlocking position. This allows the inner piston 56 to separate from theouter piston 57 by breaking the seal 55 between the two pistons. Theinner piston 56 is allowed to continue to travel to push the mixedmaterial out the dispensing tip 21.

All filling methods mentioned may be applied for each of the mentionedcapsule configurations. It is as well possible to combine fillingmethods if it is of advantage.

As foils for sealing the cartridge or to encapsulate the materials inany of the described manner, it is preferred to use multi-layer foilscontaining at least one aluminum layer. Those foils are well known inthe packaging industry. Furthermore it is preferred to use foils with atleast one sealing layer as an outer layer of the foil, preferably madeout of polyethylene, which provides for a tight seal when the foil isheat-sealed to molded polyethylene parts and/or to the sealing layer ofa second foil.

FIG. 75 shows a capsule 10 in a further embodiment similar to theseventh embodiment, and the differences will be described in thefollowing.

The piercing elements 33 for the front foil 30 (not shown) are formedintegrally with the cannula 21. The component chambers 13, 14 and thepistons 19, 20 each have circular cross sections. Each piston 19, 20 hasa channel 49 extending along its whole length and sits with its frontend in the rear portion of the allocated component chamber 13, 14.

A preferred solution for encapsulating the components in the cartridge11 and to keep them apart from one another is to close the rear end ofeach component chamber 13, 14 by hotmelt sealing and fitting the pistons19, 20 into the still soft hotmelt 64 (FIG. 54 to FIG. 56). The frontend of each component chamber 13, 14 is closed off by a sealing foil 30(not shown). When the plunger 63 of an applicator 62 (FIG. 69, FIG. 70)is advanced, the cartridge 11 and the plunger 63 are moved forwardbecause of the hotmelt seal 64 between both parts. When the cartridge 11has reached the end position in the housing 31, the foil 30 is piercedby the piercing elements or pins 33 which are arranged in the housing31, and the component chambers 13, 14 are opened. When the plunger 63 isfurther advanced, the hotmelt seal 64 breaks and the pistons 19, 20 aremoved forward thus displacing the material out of the cartridge 11.

It may be provided that the cartridge 11 is fixed by fixing elements,preferably by a “snap lock” 65 in the front-end position of thecartridge 11 (FIG. 76). The cartridge 11 is locked as soon it reachesthe front-end position in the housing 31.

Alternatively, instead of piercing the foil 30, it may be provided thatthe foil 30 ruptures because of the pressure of the paste. In this casethe cartridge 11 is already mounted in the front-end position in thehousing 31. The same snap lock 65 may be used for fixing. When theplunger 63 is advanced, the hotmelt seal 64 breaks and pressurizes thepaste which then upon exceeding a certain pressure, forces the foil 30to rupture.

As hotmelt 64 for all mentioned hotmelt seal solutions preferablypolyamide based types like Macromelt 6206 available from Henkel. Thistype of hotmelt would provide an adhesion break between the hotmelt 64and the part which is sealed. Sealed parts are preferably made out ofpolypropylene. Other glue types also those causing a cohesion break(like amorphous alpha-olefines) can also be used.

The invention has now been described with reference to severalembodiments thereof. It will be apparent to those skilled in the artthat many changes can be made in the embodiments described withoutdeparting from the scope of the invention. Thus the scope of theinvention should not be limited to the structures described in thisapplication, but only by structures described by the language of theclaims and the equivalents of those structures.

LIST OF REFERENCE SIGNS

-   10 capsule-   11 cartridge; 11′ front part of 11; 11″ rear part of 11-   12 outlet of 11, 31; outlet openings of 13, 14-   13 first component chamber-   14 second component chamber-   15 piston-   16 partition wall between 13 and 14-   17 shells-   18 foil on 17-   19 first piston-   20 second piston-   21 cannula-   22 mixer-   23 rear end of 16-   24 first foil-   25 second foil-   26 stoppers for 12-   27 sealing foil on 11-   28 sealing foil for rear openings of 13, 14-   29 piercing tip-   30 sealing foil for front end of 13, 14-   31 housing-   32 cartridge chamber-   33 piercing elements-   34 channel through 33-   35 connections between 11 and 19, 20-   36 membrane between 11 and 19, 20-   37 plugs-   38 filling nipples-   39 through-bore through 37-   40 metering or filling needles-   41 first component-   42 second component-   43 stopper-   44 overflow volume-   45 energy flow directors-   46 groove at 11-   47 hollow space-   48 porous sinter part of 19, 20-   49 channels for 64-   50 hinge between 11′ and 11″-   51 hinge between 11′ and 21-   52 locking elements-   53 cap-   54 piston assembly-   55 seal between 56 and 57-   56 inner piston-   57 outer piston-   58 stationary capsule piston-   59 lock between 56 and 57-   60 rubber seal-   61 connecting piston-   62 applicator-   63 plunger of 62-   64 hotmelt, sealant-   65 snap lock-   66 air vent channels in 19, 20-   67 bulge

What is claimed is:
 1. A capsule for two or more components of amaterial, comprising: a cartridge comprising an outlet, a firstcomponent chamber for containing a first component, and a secondcomponent chamber for containing a second component, the two componentchambers opening into the outlet; a first piston and a second piston,wherein each piston lies with its rear end outside the correspondingcomponent chamber and, when pushed forwards, press the correspondingcomponent out of its component chamber; the cartridge having an interiorwith a stepped diameter, the front area being wider than the rear area;and the component chambers being arranged in the front area; wherein thecapsule is adapted for use within an applicator having a plunger adaptedto advance both pistons to dispense the material.
 2. The capsuleaccording to claim 1, wherein the first piston is connected to or formedin one piece with the second piston.
 3. The capsule according to claim1, wherein: each component chamber is closed off at its rear end by asealing foil; and each piston lies with its front end behind the outersurface of the allocated sealing foil; and wherein the sealing foil andthe allocated piston are configured in such a way that the piston, whenadvanced into the component chamber, pierces the sealing foil about itsentire circumference.
 4. The capsule according to claim 1, wherein eachcomponent chamber is closed off at its front end by a sealing foil. 5.The capsule according to claim 1, wherein a sealing foil closes off therear opening of the cartridge.
 6. The capsule according to claim 1,wherein a cannula, in which a mixer is arranged, is mounted on theoutlet of the cartridge.
 7. The capsule according to claim 6, whereinthe cannula, in a first position, closes off the outlet of the cartridgeand, in a second position, is connected to the outlet of the cartridge.8. The capsule according to claim 1, wherein the outlet of the cartridgeis closed off by a stopper which is connected fixedly to the mixer. 9.The capsule according to claim 1, wherein the centre axis of the capsuleand of the cannula is curved.
 10. The capsule according to claim 1,wherein the capsule has means which are used for coupling the capsule toan applicator having a single plunger which is advanced when theapplicator is actuated.
 11. The capsule according to claim 1, whereinthe two pistons sit with their rear ends in the cartridge when thepiston has not yet been advanced or has been partially or completelyadvanced.
 12. The capsule according to claim 1, wherein at least one ofthe pistons is connected to or formed in one piece with the cartridge.13. The capsule according to claim 1, wherein at least one of thecomponent chambers has at least one opening closed by a seal which is afilm attached to the cartridge, and wherein the seal is formed in onepiece with the cartridge.
 14. The capsule according to claim 1, whereinthe first component chamber has a rear opening closed by the firstpiston, wherein: the first piston has a front end; the first componentchamber has a rear opening for receiving the first piston; the front endis connected to or formed in one piece with a part of the cartridgesurrounding the rear opening and closes the rear opening.
 15. Thecapsule according to claim 1, wherein each component chamber containsthe respective component.
 16. The capsule according to claim 1, furthercomprising a cannula pivotably and/or displaceably mounted on thecartridge, which in a first position closes the outlet of the cartridge,and in a second position is connected to the outlet of the cartridge.